1. Field of the Invention
This invention relates generally to a weighing funnel that holds a chemical, pharmaceutical, biological or environmental sample (referenced herein as “sample”) for transfer to a container, and more particularly, to a quantitative sample transfer device having a closed or closeable main body segment with a neck opening at each end and removable caps for plugging both neck ends, whereby at least one neck is insertable into a flask or container for transferring a chemical sample, and neck ridges for providing air release when a sample is transferred and rinsed into a flask so that none of the sample is lost during the transfer process.
2. Description of the Background Art
Weighing funnels for receiving a sample to be weighed are well known in the art and come in many sizes, ranging from 1 milliliter (ml) or less to 6 liters. With reference to the prior art drawings in FIGS. 1-3, known weighing funnels 1, such as those disclosed by Schneider in U.S. Pat. No. 6,179,022 and Des. 415,662, have a hollow and substantially cylindrical main body segment 2 with a flat bottom surface 3, a sample receiving opening 4 at one end and a pouring neck opening 5 at the opposite end. To weigh a sample, the flat bottom surface 3 of the weighing funnel 1 is placed on a weighing balance and then the sample is placed in the weighing funnel 1 through the sample receiving opening 4. Once weighed, the sample is transferred to a flask 6, or other desired container such as a volumetric flask or chemical flask 6, for testing by carefully orienting the pouring neck 5 downward and into the top of the flask 6 or other container while trying not to spill any weighed sample. Weighed sample remaining in the weighing funnel for along its sides, is rinsed into the flask by a solvent, such as methanol, saline or other desired solvent using a squirt bottle or dropper. Another method used to remove remaining weighed sample is by tapping the funnel or flask without the use of a solvent. It is very important not to lose any weighed sample to avoid having to repeat the entire process.
There are several problems with conventional weighing funnels of this variety, which all center on losing samples or material once they have been weighed resulting in erroneous analysis results, repeated tests, investigation costs and additional costs in material and labor. For instance, weighed samples are often spilled when moving the funnel to a flask 6. Another way in which weighed sample is lost is due to static, air currents, gravity or similar forces. Weighed samples are also lost when using a rinsing solvent with conventional weighing funnels, because the funnels are not closed or closeable and solvent splashes out compromising the integrity of the rinsing process and weighed sample. Another reason weighed material is lost during rinsing is because the weighing funnel makes an airtight fit in the flask or container leaving no way for air to escape as it is displaced with the sample and rinsing solvent. This keeps the air in the container from escaping during the transfer process which creates bubbles and back flow resulting in an inefficient, unreliable and erroneous transfer of material. Finally, attempting to remove remaining sample in the funnel by tapping the funnel or container invariably results in a loss of weighed material. The resulting additional costs in performing repeatedly these sample weighing and transfer procedures could be avoided if there existed a closed or closeable quantitative sample transfer device, however, there are no known funnels that adequately and effectively address these issues.
Various other funnel devices are known in the background art but they also fail to address or even contemplate the aforementioned shortcomings. For instance, U.S. Pat. Nos. 6,173,603 and 5,918,273 issued to Horn, discloses a funnel and one-piece column arrangement for retaining small quantities of chemical samples. U.S. Pat. No. 7,461,542, issued to Weisinger, discloses a funnel viscosimeter wherein a Marsh funnel is equipped with a valve at the funnel outlet. U.S. Pat. No. 5,277,234, issued to Warstler, discloses a self venting funnel having a plurality of spaced parallel channels and a spring housing and spring loaded button. U.S. Pat. No. 4,068,689, issued to Krull, discloses a funnel securable to the uncovered top of a receptacle containing dry pulverized material is provided with an encircling skirt which coacts with the funnel to define a relatively closed zone encompassing the discharge mouth of the funnel. U.S. Pat. No. 7,225,689 and U.S. Patent Application Pub. No. 2005/0142031, issued to Wickstead et al., disclose a funnel collector that collects and holds a fluid sample in order to place the sample in immediate contact with a diagnostic test strip, which reacts with the sample. U.S. Pat. No. 3,807,466, issued to Minneman, discloses a loading funnel for ammunition cases that includes a variety of interchangeable adapter tubes, each adapted to a particular size of cartridge to prevent choking or bridging of the powder for free flow directly into the cartridge. Lastly, U.S. Patent Application Pub. No. 2007/0034421, issued to Ho et al., discloses a weighing spoon having a spoon body, holder body and a level meter. The foregoing patents and published patent applications disclose devices unrelated to the problems with conventional weighing funnels, are used for entirely different purposes and comprise structure that does not address and cannot resolve the aforementioned issues.
As there are no known quantitative sample transfer devices that address the issues noted herein, there exists a need for such a device. It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed. The instant invention addresses this unfulfilled need in the prior art by providing a quantitative sample transfer device as contemplated by the instant invention disclosed herein.